<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>试验基地</title>
    <style type="text/css">
        <!--
        * { margin:0;padding:0;}
        a{ text-decoration:none; color:#FFF; width:50px; display:block;}
        ul{ list-style:none;}
        .dk{ width:350px; margin:30px auto 0 auto}
        .dk ul li{ float:left; width:50px; background:#000; margin-right:10px; text-align:center;}
        #over{ background:#39C;}
        -->
    </style>
</head>
<body>
<div class="dk">
    <ul>
        <li><a href="#">1</a></li>
        <li><a href="#">2</a></li>
        <li id="over"><a href="#">3</a></li>
        <li><a href="#">4</a></li>
        <li><a href="#">5</a></li>
    </ul>
</div>
</body>
</html>